Boring and breaking hammer with combustion engine or electromotor drive



. June 6, 1967 P.UEBEL A 3,323,60

BORING AND BREAKING HAMMER TH COMBUSTION ENGINE OR ELECTROMO DRIVE FiledJan. 18, 1965 2 Sheets-Sheet l Z WWW BORING AND BREAKING HAMMER WITHCOMBUSTION June 6, 1967 P. UEBEL 3,323,601

ENGINE OR ELECTROMOTOR DRIVE Filed Jan. 18, 1965 2 Sheets-Sheet 2 mummmmIIIIIIIIIHIIIHHI -5 /0 .M j :T N 5 MT 9 24/ 26 Z3 Z5 L6 /2 ll /2 7 I Z529 g, 27 30 I NVENTOR. PHIL 6 (/5554 BYXMW United States Patent BORINGAND BREAKING HAMMER WITH COMBUSTION ENGINE OR ELECTROMO- TOR DRIVEPhilipp Uebel, Munich, Germany, assignor to Hermann Wacker and PeterWacker, Munich, Germany Filed Jan. 18, 1965, Ser. No. 426,248 2 Claims.(Cl. 17376) The invention relates to percussion or drilling tools of thetype having a source of power or prime mover attached to the housing.More in particular, the invention concerns a boring and breaking hammerhaving a combustion engine or electromotor drive and where thetransmission of power from the prime move-r to the tool is effected byway of a driving piston, a spring system and a working piston. Tools ofthis type are known.

The invention is concerned with the problem of achieving in suchapparatus the turning of the tool in the simplest manner possible assoon as the tool raises itself from the working area. It is furthermoreintended to provide the possibility of disconnecting the turningoperation as desired, i.e., to permit the hammer to operate withoutturning movement of the tool, and finally, it is also intended to obtainsimultaneously the cooling of the tool as well as blowing out orclearing of the bottom of the hole being bored.

Boring hammers driven by elect-romotors or combustion engines are knownwhere the rotating movement for the turning of the drill is effected bya special separately driven machine element. In such an embodiment therational and tool protecting timing of an ideal machine, first blow,then rotation of the drill, while simultaneously releasing the load, isnot provided for.

Boring hammers are furthermore known where the hammer ram is connectedwith the crank drive by an oscillating spring. Besides the knownshortcomings of such an oscillating spring which is subjected tochanging loads, the hammer ram is not able to cause the rotation of thetool because this imposes an unfavorable load on the oscillating spring.Consequently, an intermediate piston has been arranged in this knownform of construction between the actual hammer ram and the tool. This,however, involved a decrease in the percussion force and an increase inthe necessary machine components.

The subject of the invention avoids the foregoing shortcomings. Inaccordance with the invention the working piston is only caused tooperate by a pressure loaded spring which permits the turning of theoperating piston with respect to the driving piston, and between thelower part of the working piston and the housing of the hammer a turningmeans is provided which can be activated or released and which, whenactivated, causes a turning of the working piston during its returnstroke. The turning movement takes place at the moment that the load isremoved from the tool.

In order to obtain the turning movement of the work piston with respectto the driving piston the invention provides spring disks or platesbelow and above the spring which is responsive only to pressure, whichdisks or plates are axially displaceable with respect to the drivingpiston and which can support themselves against abutments on the drivingpiston and also against abutments on the work piston.

In accordance with the invention the turning or twisting means comprisegrooves extending along helical lines provided in the lower part of theworking piston, a ratchet wheel which is not axially displaceable in thehousing and which is provided with lugs that engage the grooves in thework piston, and finally a ratchet for the ratchet wheel provided in thehousing.

3,323,601 Patented June 6, 1967 The ratchet for the ratchet wheel can bemoved into and out of locking or latching position by means of a latchthat can be secured in fixed position on the housing with a lockingmeans that is accessible from the outside. This provides that in thelatched position during the upward movement of the working piston thetool is always turned, and with the latch of the working pistondisengaged the tool merely moves back and forth in axial direction.

In the simplest form of construction the tool has a polygonal member,such as a square or hexagonal shaft, which may enter the lower part ofthe working piston and is interchangeable. In this manner tools ofdiiferent configuration and for different working operations may beinserted.

Finally there is also the possibility of constructing the work piston atthe same time as the piston for a pump so that the housing draws in airby way of a release or check valve, which air is compressed and can beforced to the tool through a channel in the work piston which isprovided with a check valve.

Besides avoiding the aforementioned shortcomings the invention providesa substantial simplification of the entire turning or reversing system.The apparatus may also be of very short structural length. The insertionand removal of the tool can be effected rapidly. It is not necessary inorder to blow the dust or particles out of the bore hole to use aseparate or special machine component. The work piston together with thesurrounding housing are utilized as a pump or compressor. An auxiliarysource of power and special conduits for introducing the blow air arenot required.

Further advantages and objects of the invention will become apparentwith reference to the accompanying drawings, in which:

FIG. 1 is an axial section through the boring and breaking hammer;

FIG. 2 is a section taken along the line II in FIG. 1 as the turningmeans becomes operative; 7

FIG. 3 is a partial section similar to FIG. 2 with the turning meansdisconnected; and

FIG. 4 shows the complete apparatus with the motor attached.

The boring or breaking hammer has a cylinder or housing 1 which at itsupper end may be provided with an internal combustion engine orelectromotor. The forces are transmitted by way of connecting rod 2 tothe driving piston 3 which has imparted to it in the housing an axiallyreciprocating movement. The driving piston 3 has a reduced piston orshaft portion 4 with enlarged portions 5 at the ends thereof which serveas abutments. An upper spring disk 6 and a lower spring disk 7 areguided along the reduced piston portion 4. Between the spring disks 6and 7 a compression spring 8 of helical form is provided which pressesthe spring disks 6 and 7 against the abutments 5 on the driving pistons3, 4.

The work piston 9 is mounted around the driving piston and comprises anupper abutment portion or shoulder 10 for the upper spring disk 6 and alower abutment portion or shoulder 11 for the lower spring disk 7. Thespring disks 6 and 7 thus can simultaneously engage the abutment members5 and 10 or 5 and 11. However, they may also disengage the abutmentsduring the operation of the device.

The lower part 9' of the work piston 9 is provided with grooves 12 alongthe circumference thereof, which grooves extend helically along theouter periphery of the lower part 9. For the sake of simplicity thesegrooves are shown in the drawings as grooves extending parallel to theaxis. Actually, however, they extend helically as explained above. Inthe housing 1 a ratchet wheel 13 is provided which is rotatable but notaxially movable. This ratchet wheel is provided with two inwardlyextending lugs or noses 14 which engage the lower part 9 of the workingpiston and which extend likewise along a helical path.

The outer periphery of the ratchet wheel 13 is provided with teeth 15. Alatch or pawl 16 is adapted to engage teeth and is mounted for rotationin the housing upon a pin 17. This latch is biased by a Spring 18 whichpresses the latch 16 into engagement with the teeth 15 of the ratchetwheel 13.

In order to move the latch 16 from the latched or closed position inaccordance with FIG. 2 into the released position in accordance withFIG. 3, a bolt 19 is mounted in the housing where it is axiallydisplaceable. This bolt is biased by a spring 20' and is provided with ahead portion 21 and a conical recessed portion 22. If the bolt 19 is inthe position shown in FIG. 2, then the latch 16 is adapted to enter withits rearward portion the conical recess 22 in the bolt and thus lock theratchet wheel 13.

If the bolt 19 is moved outwardly as shown in FIG. 3, then the latch 16is turned against the effect of spring 18 into release position so thatthe latch 16 does not engage the teeth 15.

The work piston 9 is simultaneously adapted as a pump piston. In thespace about lower part 9' of the work piston within the housing 1 aquantity of air may be enclosed which, as the work piston 9 movesdownwardly, reaches the tool. For this purpose a release valve or checkvalve 23 is provided in the housing 1. The work piston 9 has atransverse bore 24 and a longitudinal bore 25 which are connected witheach other. Between the bores 24 and 25 a further check valve 26 isprovided. The tool 27 has a shaft 28 with a bore 29, which at the lowerend of the tool 27 ends in an aperture 30.

The shaft 28 of the tool is of polygonal configuration, for example,square or hexagonal. It may be inserted into a corresponding bore 31 ofthe lower part 9' of the work piston 9.

The operation is as follows. In operation the drive motor imparts areciprocating movement to the connecting rod 2. This movement and theforce are transmitted to the drive piston 3. As the drive piston 3 movesdownwardly the upper spring disk 6 is carried along and compresses thespring 8. The compression spring 8 presses against the spring disk 7 andthat in turn against the abutment surface 11 of the work piston 9. Thismoves the work piston 9 downwardly. When the drive piston 3 moves againin the upward direction, then its lower abutment surface 5 carries alongthe lower spring disk 7 again compressing the compression spring 8 whichpresses against the upper spring disk 6, and thus the working piston 9is carried along in the upward direction.

In order that the turning of the tool may take place during the raisingof the working piston, it is possible in accordance with the inventionto rotate the working pis ton as it rises. If the ratchet 16 is in thelocking position in accordance with FIG. 2 and if the working piston 9moves downwardly, then the ratchet wheel 13 can rotate incounterclockwise direction in that the lugs 14 slide in the grooves 12of the working piston 9. Therefore the working piston 9 and the tool 27do not effect any rotary movement as the working piston 9 movesdownwardly.

When the working piston 9 moves upwardly, then the ratchet wheel 13 islatched, i.e., it cannot effect any rotational movement incounterclockwise direction because the latch 16 is in engagement withthe teeth 15. Since the ratchet wheel 13 is now fixed in position, theworking piston 9 is forced to move counterclockwise as it movesupwardly.

If the ratchet 16 is turned by moving the bolt 19 into the positionshown in FIG. 3 so that it disengages the teeth 15 of the ratchet wheel13, then the ratchet wheel 13 can move clockwise and counterclockwise.In that event the working piston 9 is not turned during any strokemovement.

The outward position of the bolt 19 (top position as shown in FIG. 3)can be secured by a pin 32 which is seated on the housing as the bolt 19is moved outwardly and rotated so that the bolt is held in the raisedposition by the pressure of spring 20.

As the working piston 9 moves upwardly air is drawn into the cylinder 1through the release valve 23, and as the working piston 9 movesdownwardly, the air is conduced through channels 24 and 25 and the checkvalve 26 into the tool 27 whence it arrives at the aperture 30. In thismanner the air reaches the bottom of the bore hole.

Having now described my invention with reference to the embodimentillustrated in the drawings, I do not wish to be limited thereto, butwhat I desire to protect by Letters Patent of the United States is setforth in the appended claims.

I claim:

1. Boring and breaking hammer including a motor, a housing supportingsaid motor, a driving piston connected to said motor and a workingpiston mounted in said housing, and means connecting said driving pistonfor force transmission from said motor to said working piston includingspring means comprising a compression spring subjected solely tocompression operative to reciprocate said working piston and disposed topermit the turning of said working piston relative to said drivingpiston, and releasable turning means disposed intermediate the lowerpart of said working piston and said housing and operative during thereturn stroke of said working piston to ef fect rotary movement of saidworking piston relative to said driving piston, said driving piston andsaid working piston having portions presenting abutments within saidworking piston proximate the upper and lower end of said spring, saidspring means including two spring disks one intermediate each end ofsaid spring and the adjacent abutments movable axially relative to saiddriving piston and to said working piston and alternately intoengagement with the abutments on said driving piston and the abutmentson said working piston, said turning means comprising grooves extendinghelically along the lower portion of said working piston, a ratchetwheel mounted around the lower portion of said working piston and havinga portion supported for rotary movement in said housing, said ratchetwheel having lugs extending into said grooves, a latch pivotallysupported in said housing operative to engage the teeth of said ratchetwheel, and a tool having a polygonal shaft for engagement with the lowerportion of said working piston and having an air passage extendingtherethrough, said working piston having a reduced portion defining apart of a pump including a channel having an axially extending portionand a radially extending portion in said piston, a release valve beingarranged on said housing operative to admit air around said reducedportion to said channel, said channel being connected with the airpassage in said tool to supply air through said tool, and a check valvebeing provided in said channel within said working piston.

2. Boring and breaking hammer including a motor, a housing supportingsaid motor, a driving piston connected to said motor and a workingpiston mounted in said housing, means connecting said driving piston forforce transmission from said motor to said working piston includingspring means comprising a compression spring subjected solely tocompression operative to reciprocate said working piston and disposed topermit the turning of said working piston relative to said drivingpiston, and releasable turning means disposed intermediate the lowerpart of said working piston and said housing and operative during thereturn stroke of said working piston to effect rotary movement of saidworking piston relative to said driving piston, said driving piston andsaid working piston having portions presenting abutments within saidWorking piston proximate the upper and lower end of said spring, saidspring means including two spring disks one intermediate each end ofsaid spring and the adjacent abutments movable axially relative to saiddriving piston and to said working piston and alternately intoengagement with the abutments on said driving piston and the abutmentson said working piston, said turning means comprising grooves extendinghelically along the lower portion of said working piston, a ratchetwheel mounted around the lower portion of said working piston and havinga portion supported for rotary movement in said housing, said ratchetwheel having lugs extending into said grooves, and a latch pivotallysupported in said housing operative to engage the teeth of said ratchetwheel, said latch being associated with a spring biased bolt mountedexternally of said housing, said bolt having a recessed portion forengagement by the rear portion of said latch when in operative positionand a portion operative to move said latch out of engagement with saidratchet wheel.

References Cited UNITED STATES PATENTS FRED C. MATTERN, JR., PrimaryExaminer.

L. P. KESSLER, Assistant Examiner.

1. BORING AND BREAKINGHAMMER INCLUDING A MOTOR, A HOUSING SUPPORTINGSAID MOTOR, A DRIVING PISTON CONNECTED TO SAID MOTOR AND A WORKINGPISTON MOUNTED IN SAID HOUSING, AND MEANS CONNECTING SAID DRIVING PISTONFOR FORCETRANSMISSION FROM SAID MOTOR TO SAID WORKING PISTON INCLUDINGSPRING MEANS COMPRISING A COMPRESSION SPRING SUBJECTED SOLELY TOCOMPRESSION OPERATIVE TO RECIPROCATE SAID WORKING PISTON AND DISPOSED TOPERMIT THE TURNING OF SAID WORKING PISTON RELATIVE TO SAID DRIVINGPISTON, AND RELEASABLE TURNING MEANS DISPOSED INTERMEDIATE THE LOWERPART OF SAID WORKING PISTON AND SAID HOUSING AND OPERATIVE DURING THERETURN STROKE OF SAID WORKING PISTON TO EFFECT ROTARY MOVEMENT OF SAIDWORKING PISTON RELATIVE TO SAID DRIVING PISTON, SAID DRIVING PISTON ANDSAID WORKING PISTON HAVING PORTIONS PRESENTING ABUTMENTS WITHIN SAIDWORKING PISTON PROXIMATE THE UPPER AND LOWER END OF SAID SPRING, SAIDSPRING MEANS INCLUDING TWO SPRING DISKS ONE INTERMEDIATE EACH END OFSAID SPRING AND THE ADJACENT ABUTMENTS MOVABLE AXIALLY RELATIVE TO SAIDDRIVING PISTON AND TO SAID WORKING PISTON AND ALTERNATELY INTOENGAGEMENT WITH THE ABUTMENTS ON SAID DRIVING PISTON AND THE ABUTMENTSON SAID WORKING PISTON, SAID TURNING MEANS COMPRISING GROOVES EXTENDINGHELICALLY ALONG THE LOWER